1. Field of the Invention
This invention relates to a cutter bit and support therefore and more particularly to an improved resilient detent means which not only holds the bit within a bit holding socket, but provides for easy release of the bit for replacement purposes.
2. Description of the Prior Art
Rotary Detent means for cutter bits are well known in the art and are generally shown in U.S. Pat. Nos. 3,166,052 and 3,057,609. U.S Pat. No. 3,166,052, particularly FIGS. 23-26, discloses a rotary bit holder which is embedded in an elastomeric material. The retaining element is eccentric and can be rotated with a socket wrench into and out of engagement with a recess in the bit shank. The compression of the elastomeric material provides the retaining force against the bit shank.
U.S. Pat. No. 3,057,679 shows an additional detent scheme utilizing elastomeric material and a recess in the bit shank. In this design, the downward force of inserting the bit forces the retaining device against a deformable elastomeric member, thereby permitting insertion of the bit but allowing the retaining device to spring into the socket in the bit shank. A similar device designed by the same inventor is shown in U.S. Pat. Nos. 2,965,365 and 3,088,721.
Patents showing devices extending parallel to the side of the bit shank and engaging indentations therein are shown generally in U.S. Pat. Nos. 1,140,173 and 3,362,754 and 3,751,115. A pin-engagement retaining device for a cutter bit having a shank portion is best shown, however, in South African Patent application No. 65/6900. None of the U.S. patents or the South African applications disclose an offset locking pin held in locking position by a resilient anti-rotational retainer as is taught by applicant.